fix: extraneous coverage for --project (fix #6331)

[gtbuchanan]

Description

Coverage was reported for projects outside of the specified project filter. For example, given a monorepo with two projects, p1 and p2, vitest run --coverage --project=p1 reported coverage for code from p2 at 0% because no tests from p2 were run.

Resolves: #6331

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[gtbuchanan]

@AriPerkkio Does this align with what you were thinking? I still need to familiarize myself with how the tests are written, but I wanted to ensure I was on the right track first.

Also, should I move the duplicate code to a common location (like BaseCoverageProvider)?

[AriPerkkio]

This change would only filter out uncovered files outside the workspace project's root. We should filter out covered files too.

To do this, we'll need to make this.testExclude an array, and create one for each project with their roots.

vitest/packages/coverage-istanbul/src/provider.ts

Lines 34 to 35 in 9be32fb

	this.testExclude = new TestExclude({
	cwd: ctx.config.root,

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[gtbuchanan]

That should do it. It seems to work for my project. I will add tests when I figure that out 🙂

As an aside, I wasn't able to move the duplicate code to BaseCoverageProvider because vitest/node doesn't reference test-exclude. I figured it wasn't worth adding the extra reference for this fix.

[AriPerkkio]

Looks good so far.

As an aside, I wasn't able to move the duplicate code to BaseCoverageProvider because vitest/node doesn't reference test-exclude. I figured it wasn't worth adding the extra reference for this fix.

That's okey for now. In #7837 we'll remove test-exclude completely and utilize packages that are available in vitest package. That allows re-using logic from BaseProvider.

For test cases we'll need to verify following:

• When --project filter is passed, files outside that project are excluded. This means covered and uncovered files.
• When --project filter is not passed, files in projects and in the root should be visible.

You can add fixtures in test/coverage-test/fixtures/workspaces and create test cases in new file test/coverage-test/test/workspace.test.ts for example.

[AriPerkkio]

Hey @gtbuchanan, do you have any time to finalize this PR? I'm also happy to take over and finish it if you prefer that. Thanks for all the work so far! 💯

[gtbuchanan]

@AriPerkkio I would have liked to finish it myself, but I'm running into some issues:

1. I figured out how to write the tests, but the one testing my fix is actually failing. I'm trying to debug the coverage test in VS Code using these steps, but clicking "Run and Debug" immediately stops debugging. Do you have any tips? Is there a specific file I'm supposed to have open?
2. Obviously, my branch is now outdated. Out of curiosity, I added my unit tests on top of main to make sure one would fail, but they actually passed. I'm assuming my test is just wrong since main doesn't appear to have a fix for this. Will you glance at my tests to see if something stands out?

EDIT:
Disregard 2. There must have been some caching involved. I picked the PR back up on my work computer and the test fails there as expected. Now to reapply the fix...

[gtbuchanan]

I didn't figure out how to debug the coverage tests in VS Code, but I was able to get everything working! It seems to work without updating isIncluded, but let me know if I'm missing something.

[AriPerkkio]

There must have been some caching involved. I picked the PR back up on my work computer and the test fails there as expected. Now to reapply the fix...

The test cases are running against built assets so you'll need to run pnpm build or pnpm dev before running the test cases. That might explain the caching issue.

I didn't figure out how to debug the coverage tests in VS Code

These test cases are running "Vitest inside Vitest" so it's likely that VS Code extension is unable to inspect those.

[AriPerkkio]

Small improvements, otherwise this is looking good!

Btw as this PR is from a Github organization account (energyworldnet), Vitest maintainers cannot push any changes to your PR branch. Usually I would fix small errors like this myself and push changes to your branch directly, but now it's not possible due to permission requirements.

[AriPerkkio]

Looks good, thanks for the PR @gtbuchanan! 💯